NAME

SYNOPSIS

DESCRIPTION

The
aio_cancel()
function attempts to cancel outstanding asynchronous I/O requests
for the file descriptor
fd.
If
aiocbp
is NULL, all such requests are canceled.
Otherwise, only the request
described by the control block pointed to by
aiocbp
is canceled.
(See
aio(7)
for a description of the
aiocb
structure.)

Normal asynchronous notification occurs for canceled requests (see
aio(7)
and
sigevent(7)).
The request return status
(aio_return(3))
is set to -1, and the request error status
(aio_error(3))
is set to
ECANCELED.
The control block of requests that cannot be canceled is not changed.

If the request could not be canceled,
then it will terminate in the usual way after performing the I/O operation.
(In this case,
aio_error(3)
will return the status
EINPROGRESSS.)

If
aiocbp
is not NULL, and
fd
differs from the file descriptor with which the asynchronous operation
was initiated, unspecified results occur.

Which operations are cancelable is implementation-defined.

RETURN VALUE

The
aio_cancel()
function returns one of the following values:

AIO_CANCELED

All requests were successfully canceled.

AIO_NOTCANCELED

At least one of the
requests specified was not canceled because it was in progress.
In this case, one may check the status of individual requests using
aio_error(3).

AIO_ALLDONE

All requests had already been completed before the call.

-1

An error occurred.
The cause of the error can be found by inspecting
errno.

ERRORS

EBADF

fd
is not a valid file descriptor.

ENOSYS

aio_cancel()
is not implemented.

VERSIONS

The
aio_cancel()
function is available since glibc 2.1.

ATTRIBUTES

For an explanation of the terms used in this section, see
attributes(7).

Interface

Attribute

Value

aio_cancel()

Thread safety

MT-Safe

CONFORMING TO

POSIX.1-2001, POSIX.1-2008.

EXAMPLE

SEE ALSO

COLOPHON

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